Viessmann Boiler FR Fault Code

The Viessmann fault code FR means, it’s likely there’s a problem with the fan and here we have Q & A or require an engineer for an emergency boiler repair.

The Viessmann Boiler Fault Code FR Error Common Q & A

Just below, we have a list of common questions relating to the FR fault code on the Viessmann Boiler.

What does the FR fault code mean on my Viessmann boiler?
What is the purpose of the fan on my Viessmann boiler?
Is there a way to fix the FR fault code on a DIY basis?
What should my engineer be looking out for, when trying to fix the FR fault code?
How will my boiler repair company know if it’s the fan that’s causing the issues with my Viessmann boiler?
Which wires and connections will my boiler engineer need to check next?
If the fan on my Viessmann boiler needs to be replaced, how much will it cost?
How can the burner contribute to the FR fault code being displayed?
What does the PCB have to do with the FR fault code on my Viessmann boiler?
If my PCB needs replacing, how much is this going to cost?
My boiler engineer thinks water damage has occurred, how can this be fixed?

What does the FR fault code mean on my Viessmann boiler

If your boiler is having problems, it’s going to show a fault code on the display panel. In the case of the FR error code on Viessmann boilers, it’s likely there’s a problem with the fan.

Fans are mechanical parts and can cause issues over time. Typically, we find that the fan stops working completely due to wiring issues. However, in the case of the FR fault code, the fan is running when it shouldn’t be.

Another potential cause of the FR fault code is the burner. If the burner has gone into fault mode, this is the culprit, rather than the fan.

What is the purpose of the fan on my Viessmann boiler

The fan is an extremely important component on your boiler. Its job is to create a draught so that harmful gases can be vented out of the flue. In fact, your boiler won’t fire up until the fan is running. If it was to burn gas without the fan being operational, these harmful gases could build-up in the boiler, making it dangerous.

Due to this being a component that ensures that your boiler is operating safely, when it’s not functioning correctly, the boiler will lockout.

It’s the printed circuit board on your boiler that controls the fan, the same way in which it does with many other important electrical components. It gives signals for it to operate, as well as when to stop operating.

In the case of the FR fault code, although the PCB has given the signal for the fan to stop operating, the signal the PCB is receiving shows that the fan is still trying to vent gases out of the flue.

Is there a way to fix the FR fault code on a DIY basis

There are some fault codes whereby there’s a simple DIY fix. However, the FR fault code isn’t one of them.

To work on the issue causing the FR error code to be displayed, the boiler will need to be taken apart. You shouldn’t dismantle the boiler unless you are Gas Safe registered and therefore, have the accreditation and experience to work on gas boilers.

If a fault code is being displayed, don’t try to reset your boiler to fix the problem. A reset is designed to be used when the problem has been found and fixed. Resetting your boiler won’t achieve anything. The second the PCB recognises that the problem hasn’t been rectified, it will lockout again, displaying the same FR fault code as before.

What should my engineer be looking out for, when trying to fix the FR fault code

Your engineer will first, want to check the fan. They’ll be focusing their attention on the:

100A cable
All other cables and connections
The fan unit itself

Although the fan is usually to blame for the FR fault code, there are two other potential culprits.

That includes both the burner, and the PCB. So, after ensuring that the fan isn’t the issue, your boiler engineer will want to check out both components for wear, tear, and damage.

How will my boiler repair company know if it’s the fan that’s causing the issues with my Viessmann boiler

The first thing your boiler engineer is going to need to do is to check the 100A cable that’s connected to your fan. When the FR fault code is displayed on Viessmann boilers and the fan is to blame, this is the mostly cause of the fault.

Your boiler engineer will visually inspect the 100A cable, checking for signs of wear, tear and damage. They’ll also want to make sure that the cable is secured. If there’s even the slightest sign of wear, or a loose connection, the fan isn’t not going to be able to communicate with the PCB correctly. And, this could lead to the fan continuously running, even when it shouldn’t be.

If the 100A cable looks like it’s in good condition, your boiler repair company can double check, by testing the cable with a multi-meter. If the cable isn’t getting power, it will need to be replaced. If it is getting power, they’ll need to start testing other sections of wiring.

Which wires and connections will my boiler engineer need to check next

Your boiler repair company will need to check any wires and connections that are connected to the fan and PCB. One small problem could lead to a complete lack of communication between the two components. And, that’s going to mean that the fan runs when it shouldn’t, or that the PCB thinks the fan is running, even when it isn’t.

Like the 100A cable your boiler repair company will have already checked, a quick visual inspection will highlight any major issues. If it doesn’t they’ll need to use a multi-meter to figure out at which point in the circuit there’s a break, or a weak signal. Any loose or damaged wires/connections will need to be secured, replaced or repaired.

If all tests are positive, that leaves them with the fan. Like wires and connections, the fan also needs to be tested. If the fan is faultyfan is faulty and can’t be repaired, it will need to be replaced.

If the fan on my Viessmann boiler needs to be replaced, how much will it cost

If there’s a fault with the fan that can’t be repaired, you’ll need a replacement. Typical fan replacement costs sit in the £250-300 range. You should expect the job to take around one working day, although your engineer is likely to have to order in parts from their local supplier.

How can the burner contribute to the FR fault code being displayed

Another potential cause of the FR fault code being displayed, is that the burner has gone into fault mode. If your boiler engineer suspects that the burner is the problem, it’s likely that there’s been debris build-up in the burner, and this is causing the error.

Over time, carbon can build-up in the burner. This isn’t a huge problem, unless the build-up is exceptionally high. However, the burner gets its fuel supply from a small jet. And, this small jet is susceptible to getting blocked up. One small piece of debris is enough to cause a blockage, and that’s going to put the burner into fault mode.

Luckily, the fix is a simple one, and rarely an expensive one. Your boiler repair company will be able to remove the jet, and then clean it. Once the jet has been cleaned, it can be refitted. At this point, your Gas Safe engineer can reset your boiler, which should get rid of the lockout, FR fault code, and have your boiler working again.

What does the PCB have to do with the FR fault code on my Viessmann boiler

Every single fault code on your boiler, is connected to the PCB. And, that’s because the PCB gives and receives signals to all components, constantly monitoring them thanks to a range of sensors. If it receives a signal that a part isn’t working when it should be (or vice-versa), then it’s going to lockout and display a fault code.

In the case of the FR fault code, the PCB has been given the signal to show the fan is running, even when it shouldn’t be. But, one potential cause of the error could be that the PCB is at fault, the signals it’s receiving are wrong, and the fan has in fact, stopped working when it should have.

As your boiler repair company did with the wiring and connections on the fan, they’ll want to test every wire and connection to the PCB. And, they’ll also want to test the PCB itself. If there are any electrical problems here, this could explain the FR fault code.

If my PCB needs replacing, how much is this going to cost

If the problems do stem from the PCB and the unit is beyond repair, a replacement is going to be needed. Typically, we’d expect a PCB unit to cost in the region of £400-500, and that’s going to take around one working day to replace.

Before getting the PCB replaced, it’s worth considering all the options. New boiler installations can start as low as £1,800. So, if you’re already planning on spending £400-500, it’s worth getting your boiler engineer to check over other expensive components. It might be they’re excessively worn, and a replacement boiler would be the most cost-effective option in the long term.

My boiler engineer thinks water damage has occurred, how can this be fixed

Besides simply fixing a loose connection, damaged wiring and components such as the fan or PCB, the root cause needs to be found. If that root cause is water damage, your boiler engineer needs to fix leaks in your boiler, before repairing expensive components.

Typically, we’d expect leaks to be coming from the heat exchanger or pump.

Heat exchanger leaks are generally caused by cracks on the exchanger plate. There’s no cheap fix, as the heat exchanger will need to be replaced, at a cost of over £400.

However, the pump can usually be reconditioned if that’s the cause of the leak. Typically, a service kit that includes new seals, is going to do the job.

Other Viessmann boiler issues

For more boiler issues regarding the Viessmann Boiler then please visit the Ideal Boiler Problems And Cures page.

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